Apparatus and method for terminating probe apparatus of semiconductor wafer

ABSTRACT

A probe apparatus and method of terminating a probe that probes a semiconductor device with a signal cable from a tester side by side at a proximal end of the probe and a distal end of the signal cable. In one embodiment, the probe apparatus includes: a chassis; a dielectric block mounted in the chassis for retaining the probe, the probe extending on the chassis from a proximal end of the probe to the dielectric block, extending through the dielectric block, and projecting from the dielectric block towards the semiconductor device at a distal end of the probe; and a terminating apparatus, mounted in the chassis, for terminating the proximal end of the probe with a distal end of the signal cable side by side.

FIELD OF THE INVENTION

The present invention generally relates to semiconductor test equipment,and more particularly, to a probe apparatus used in semiconductor testequipment for electrically probing devices on a semiconductor wafer.

BACKGROUND OF THE INVENTION

The semiconductor industry has a need to access many electronic deviceson a semiconductor wafer. As the semiconductor industry grows anddevices become more complex, many electrical devices, most commonlysemiconductor devices, must be electrically tested, for example, forleakage currents and extremely low operating currents. These currentsare often below 100 fA. In addition, the currents and devicecharacteristics are often required to be evaluated over a widetemperature range to understand how temperature affects a device. Also,because of materials characteristics of dielectrics, it is oftendifficult to test characteristics of semiconductor devices in a wideoperating temperature range.

To effectively measure at currents below 100 fA (Femto Ampere), ameasurement signal must be isolated from external electricalinterference, leakage currents through the dielectric material,parasitic capacitance, triboelectric noise, piezoelectric noise, anddielectric absorption, etc.

Accordingly, there is a need for improved semiconductor test equipmentfor electrically probing semiconductor devices at low currents over awide temperature range.

SUMMARY OF THE INVENTION

To solve the above and the other problems, the present inventionprovides a probe apparatus having a probe that probes a semiconductordevice and terminates with a signal cable side by side. Moreparticularly, the present invention provides a probe apparatus having aprobe that probes a semiconductor device and terminates with a signalcable side by side at a proximal end of the probe and a distal end ofthe signal cable.

In one embodiment of the present invention, the probe apparatusincludes: a chassis; a dielectric block mounted in the chassis forretaining the probe, the probe extending on the chassis from a proximalend of the probe to the dielectric block, extending through thedielectric block, and projecting from the dielectric block towards thesemiconductor device at a distal end of the probe; and a terminatingapparatus, mounted in the chassis, for terminating the proximal end ofthe probe with a distal end of the signal cable side by side.

Still in one embodiment, the probe extends along a dielectric platetowards a semiconductor device at a distal end of the probe. The signalcable extends along the dielectric plate towards a test equipment at aproximal end.

Further, the present invention provides a method of terminating a probethat probes a semiconductor device with a signal cable from a tester.The method includes the steps of stripping back at least one layer ofthe signal cable and at least one layer of the probe; crimping aproximal end of the probe with a distal end of the signal cable side byside; and mounting the probe and the signal cable in a chassis, whereina distal end of the probe is extended towards the semiconductor device,and a proximal end of the signal cable is extended towards the tester.

These and other advantages of the present invention will become apparentto those skilled in the art from the following detailed description,wherein it is shown and described illustrative embodiments of theinvention, including best modes contemplated for carrying out theinvention. As it will be realized, the invention is capable ofmodifications in various obvious aspects, all without departing from thespirit and scope of the present invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of one embodiment of a probingapparatus in accordance with the principles of the present invention.

FIG. 2 illustrates a bottom view of one embodiment of the probingapparatus in accordance with the principles of the present invention.

FIG. 3 illustrates a partial top view of one embodiment of the probingapparatus in accordance with the principles of the present invention.

FIG. 4 illustrates an enlarged partial, perspective view of oneembodiment of the probing apparatus in accordance with the principles ofthe present invention.

FIG. 5 illustrates a cross-sectional view of one embodiment of theprobing apparatus in accordance with the principles of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIGS. 1-5, a probe apparatus 100 in accordance with the principles ofthe present invention includes a chassis 102, a dielectric block 104mounted in the chassis 102 for retaining a probe 106. The probe 106extends on the chassis 102 from a proximal end 108 of the probe 106 tothe dielectric block 104, extending through the dielectric block 104,and projecting from the dielectric block 104 towards a device, e.g.semiconductor device (not shown), at a distal end 110 of the probe 106.

The apparatus 100 also includes a terminating apparatus 112, mounted inthe chassis 102, for terminating the proximal end 108 of the probe 106with a distal end 114 of a signal cable 116 side by side.

Also, the probe 106 extends along a dielectric plate 118 towards thesemiconductor device (not shown) at the distal end 110 of the probe 106.The signal cable 116 extends along the dielectric plate 118 towards atest equipment (not shown) at a proximal end 120.

Also shown in FIG. 5, the probe 104 includes a probe conductor 122surrounded by a dielectric layer 124. The dielectric layer 124 is coatedby a conductive coating layer 126 which is covered by a conductive hightemperature foam 128. A strain relief clamp 130 clamps the probe 106onto the dielectric plate 118.

In FIG. 5, the signal cable 116 includes a center conductor 132surrounded by a dielectric layer 134. The center conductor 132 may be acoaxial or tri-axial signal wire. The dielectric layer 134 is covered bya conductive triboelectric low noise coating 136. The coating 136 iscovered by a conductive guard 138. An insulator jacket 140 is used tocover the conductive guard 138. In addition, a strain relief screw 142and a strain relief washer 144 clamp the signal cable 11 onto thedielectric plate 118.

The terminating apparatus 112 further includes a crimp 146. The crimp146 terminates the proximal end 108 of the probe 106 with the distal end114 of the signal cable 116 side by side.

In FIG. 5, a conductive high temperature foam 148 is disposed betweenthe probe 106 and the dielectric plate 118 on one side, and between thesignal cable 116 and the dielectric plate 118 on the other side. Theremaining part of the foam 148 is disposed within an opening area 150 ofthe dielectric plate 118.

The numerous innovative teachings of the present application will bedescribed with particular reference to the presently preferredembodiments, wherein these innovative teachings are advantageouslyapplied to the particular problems of a probe apparatus for measuringlow currents with a wide operating temperature range in probing asemiconductor device. However, it should be understood that theseembodiments are only examples of the many advantageous uses of theinnovative teachings herein. In general, statements made in thespecification of the present application do not necessarily limit any ofthe various claimed inventions. Moreover, some statements may apply tosome inventive features but not to others. In general, unless otherwiseindicated, singular elements may be in the plural and visa versa with noloss of generality.

The following terms are particularly described throughout thedescription:

Semiconductor Device not Limitive

The present invention is particularly suitable for probing semiconductordevices, but the use of the present teachings is not limited to probingsemiconductor devices. Other devices, such as biological devices, may beapplied to the present invention teachings. Thus, while thisspecification speaks in terms of probing ‘semiconductor’ devices, thisterm should be interpreted broadly to include probing any suitabledevice.

Low Current not Limitive

The present invention solves the problem of measuring currents below 100fA, but the current range of the present teachings is not limited tobelow 100 fA. For example, the present invention may be applied tomeasure the currents at or above 100 fA in a semiconductor device. Thus,while this specification speaks in terms of ‘low currents’ or ‘measuringcurrents below 100 fA’, these terms should be interpreted broadly toinclude any current that flows through a semiconductor device whichcould be at or above 100 fA.

Wide Temperature not Limitive

The present invention solves the problem of measuring currents of asemiconductor device in a narrow or limited operating temperature range.The present teachings do not limit to a specific operating temperaturerange. The present application allows a tester to electrically probesemiconductor devices over a wide operating temperature range, not onlyat a low operating temperature but also a high operating temperature,e.g. an operating temperature up to 300 C and beyond. Thus, while thisspecification speaks in terms of ‘wide temperature range or measuringcurrents in a wide operating temperature range’, these terms should beinterpreted broadly to include any suitable operating or testingtemperature range of a semiconductor device.

Size not Limitive

The present invention solves the problem of measuring currents andvoltages of a semiconductor device using a compact probing apparatus.However, nothing in the teachings of the present invention limitsapplication of the teachings of the present invention to a larger orsmaller probe apparatus. Advantageous use of the teachings of thepresent invention may be had with a probe apparatus of any size.

Materials not Limitive

Throughout the discussion herein there will be examples provided thatmake reference to materials, such as ceramic, in regards to dielectricblock. The present invention does not recognize any limitations inregards to what types of materials may be used in affecting theteachings of the present invention. One skilled in the art willrecognize that any suitable material may be used with no loss ofgenerality in implementing the teachings of the present invention.

From the above description and drawings, it will be understood by thoseof ordinary skill in the art that the particular embodiments shown anddescribed are for purposes of illustration only and are not intended tolimit the scope of the present invention. Those of ordinary skill in theart will recognize that the present invention may be embodied in otherspecific forms without departing from its spirit or essentialcharacteristics. References to details of particular embodiments are notintended to limit the scope of the invention.

What is claimed is:
 1. A probe apparatus for probing a device on asemiconductor wafer, comprising: a probe for probing a semiconductordevice, the probe having a proximal end and a distal end, the probecomprising: a probe conductor, a dielectric layer disposed around theprobe conductor, a conductive coating layer covering and being disposedaround the dielectric layer of the probe, and a conductive hightemperature layer disposed around the conductive coating layer; achassis; a dielectric block mounted in the chassis for retaining theprobe, the probe extending from the proximal end of the probe towardsthe dielectric block, extending through the dielectric block, andprojecting from the dielectric block towards the semiconductor device atthe distal end of the probe; and a dielectric plate mounted on thechassis, the probe extending from the proximal end of the probe alongthe dielectric plate towards the dielectric block and the semiconductordevice at the distal end of the probe, the probe being clamped onto thedielectric plate.
 2. The probe apparatus according to claim 1, whereinthe probe conductor is configured to be electrically connected to asignal conductor.